Shelly’s Flood Gen4 Sets the Stage for Leak and Weather-Based Automations

Shelly’s Flood Gen4 adds smart automation to leak detection, letting integrators protect homes (and systems) before water damage happens.
Published: November 17, 2025

As a famous fantasy icon once said, “Winter is coming.” Though, instead of White Walkers, one of the more common issues homeowners need to be concerned about in the winter are pipes bursting. In comes Shelly, then, with the Flood Gen4, a water leak and flood detector that supports Matter, Wi-Fi, Zigbee, as well as full local control.

The Flood Gen4 joins Shelly’s recently announced Gen4 portfolio, a series designed around multi-protocol interoperability and consistent cross-device behavior across relays, sensors and control panels.

Design and Features of the Shelly Flood Gen4

Despite its compact footprint, the Shelly Flood Gen4 offers broad detection capabilities thanks to a 6.5-foot extendable sensor cable that can be linked up to roughly 500 feet, allowing it to be used in a range of locations, from tight spaces beneath sinks to larger areas such as basements.

In addition to the traditional flood detection, the sensor also has a secondary rain mode, which Shelly says also allows it to monitor for outdoor moisture and act as a trigger for any weather-related automations in a broader smart home system.

In fact, when connected to compatible relays or smart shut-off valves, the device can also be used to cut power to appliances or close off water flow entirely. Notifications are delivered through the Shelly app in the event of such an incident. The device also features an integrated audible alarm, however, making it the leak equivalent of a smoke alarm.

Power for the sensor is supplied by four replaceable AA batteries, with Shelly estimating up to two years of operation depending on usage and network conditions.

Water Leak Detection: A Small, But Growing Market

While not being the biggest or most glamorous part of a smart home, water leak detection still commands attention from homeowners, with this year’s CE Pro 100 Brand Analysis revealing that the emerging category is still on its way up, with there being plenty of room to grow among the current slew of options.

It’s not too difficult to see why, though, as outside of the raw havoc of a hurricane or fire, water damage can often be very hard to detect. And in most cases, once it becomes noticeable, it’s usually past the point of no return for the homeowner.

That said, the segment’s relatively small profusion currently might imply a lack of awareness among project clients, so integrators shouldn’t assume to naturally start seeing client interest if they were to suddenly start carrying the products.

Though, integrators have plenty of reasons to like the little sensors, too, for, as far as insurance investments go, being able to cut off leaks at the source is a surefire way to prevent valuable electrical equipment from getting damaged, and Shelly’s option even provides the ability to cut off power, as well.

What Else Integrators Should Know

As a Gen4 device, the Shelly Flood shares the same set of universal features and expanded connectivity as the rest of the portfolio with an emphasis on scalability and cross-device compatibility.

Additionally, the Flood Gen4 carries an MSRP of $32.99, with the sensor now being available for purchase directly either from Shelly directly, or through authorized distributors. Add-on accessory sensor cables (6.5 feet) are also available for $7.49.

Note: For more details on Shelly’s Gen4 portfolio, as well as Shelly’s recently announced pro-channel resources, follow the links to their respective articles.

Strategy & Planning Series
Strategy & Planning Series
Strategy & Planning Series
Strategy & Planning Series
Strategy & Planning Series
Strategy & Planning Series
Strategy & Planning Series